During certain types of surgical procedures such as, for example, those involving the removal of cataracts from the eyes, irrigation/aspiration machines are used to provide irrigation to the operative site while removing or aspirating fluids and body tissue from the operative site. One such machine is sold under the trademark Cavitron/Kelman by Coopervision. These machines have become widely used in many types of surgery.
A disposable set-up kit consisting of irrigation and aspiration tubing is provided to the surgical team for connecting the machine to the instrument being used by the surgeon, to the sterile fluids being used for irrigation, and to the disposable collection means which receives the fluids and tissue aspirated from the site. A new set-up kit is provided with each surgical operation and is disposed of after the surgery is performed. The aforesaid set-up kit includes a disposable, plastic releasable connector called a "cam lock tee" affixed to and part of the aspiration tubing. The "cam lock tee" is snapped into place in a grooved, aspiration line receptacle on the front of the machine. This receptacle has an air orifice therein. When the connection is made, the orifice is aligned with an orifice in the "cam lock tee." So assembled there is direct communication between the aspiration line and the interior of the irrigation/aspiration machine.
Although the set-up kits are disposable and all of the instruments are sterilized prior to each surgical procedure, there are still resulting contamination problems caused by aspirant working its way into the interior of the irrigation/aspiration machines causing contamination therein, which may either interfere with proper function of the machine, or be blown back into subsequent aspiration lines. Further, aspirant in the machine may lead to the growth of bacteria and micro-organisms. In normal use air is taken into the machine and blown out. Air is taken in so that the air pressure in the line can be monitored. At other times the air outlet or air jet outlet is used to provide air into the aspiration tube at any time the suction pressure in the tube has increased to an undesirable level. This is the way the machine conventionally operates. Injection of air through the orifice breaks the suction pressure. The aforementioned growth of micro-organisms and bacteria can also cause problems at a later time when such contaminants leak into the operating room environment and possibly cause cross-contamination. Also, the injection of air through the nozzle or outlet on the same or subsequent operative cases may cause the bacteria and micro-organisms to be blown into the aspiration tube, from whence such contaminants back up to the site of the operation or contaminate the aspirant which may be subjected to later pathological tests.
In addition to contamination problems, bacause of the limited tolerance controls which can be effected on a disposible plastic "cam lock tee," the connection between the "cam lock tee" and the machine orifice is sometimes difficult to achieve properly. Sometimes the orifices do not align properly; sometimes the connection may be loose.
It was to overcoming these problems with steriliztaion of the equipment, isolation of aspirant from the equipment, and facilitating the connection of the tube that the present inventor turned his attention. The present invention is directed to an improved set-up kit in which the "cam lock tee" is replaced by a machined metallic fitting and is no longer part of the disposable aspiration line. Further, a filtering device is now inserted between the machine and the tubing. The remaining portions of the set-up kit with the irrigation/aspiration tubing and the connections for surgical instruments, I/V's and collectors, are conventional. Because of the way the connection is now made and because of the hydrophobic filter, there is a significant decrease in the growth and spreading of micro-organisms and bacteria. For the first time, the patient is isolated from the irrigation/aspiration machine and a sterile environment is maintained; aspirant is kept out of the machine; and the connection of an aspiration tube may be made more quickly, more easily, and more reliably.
In a first approach, the machined fitting includes a body portion which attaches to the grooved aspiration line receptacle by simply snap locking thereon in a manner similar to the disposable "cam lock tee." A nozzle portion of the fitting is a cylindrical tube which screws onto a nipple on the body portion. The disposable tube includes a filter device that has a male portion extending therefrom that inserts into the aforesaid nozzle. Thus assembled, the filter lies between the air orifice and the aspiration tube, preventing any flow of aspirated fluids into the air orifice, and also preventing any injection of micro-organisms from the air orifice back into the aspiration line. Thus the aspiration tubing is isolated from the interior of the machine with the exception of air flow. The filter is a small hydrophobic filter of a type which will be described in detail below. The permanent machined fitting can be removed from the machine periodically and sterilized. It is significantly more durable than the disposable type used on the Cavitron/Kelman set-up kit; it provides a tight seal around the air orifice and thus improves the pressure control of the machine; and it provides a far easier technique to connect and assemble the set-up kit because it is a simple matter of inserting the male portion of the filter housing into the female portion of the fitting.
In a modified, preferred approach, the nozzle portion is hexagonally shaped and includes a threaded projection which screws into the body portion of the machined fitting. A removable locking member fits over the hexagonal nozzle to prevent rotation or loosening of the nozzle portion which may result as disposable tubing kits are emplaced and removed.
In the earlier embodiment, the nozzle occasionally became partially unscrewed as nurses or other personnel assembled the disposable portions of the set-up kit to the nozzle. It was determined that some means for preventing rotation of the nozzle was necessary and the inventor conceived and developed the removable locking tab or bracket which snaps into place over the hexagonal nozzle. The locking tab/bracket prevents any rotation or loosening of the nozzle until desired.
It is one object of the present invention to form an aspiration tube connection for machines of the type described in which the connection is made easier and simpler.
It is another object of the present invention to form an aspiration tube connection for machines of the type described in which the nozzle connection is made more secure against displacement.